Implementations directed to providing a computer-implemented method comprising receiving, from a motion sensing device, a plurality of image frames that includes information regarding a plurality of animals housed in a group-housed environment, determining a coordinate space of the group-housed environment based on an analysis of a first image frame of the image frames, generating, based on the analysis of the first image frame, an ellipsoid model for each animal based on defined surface points for each animal weighted according to a likely proximity to a crest of a spine of the respective animal, and tracking a position and an orientation of each animal within the image frames by enforcing shape consistency of the ellipsoid models, and adjusting the position of each of the ellipsoid models based on the defined surface points for each animal and a maximum likelihood formulation of a movement distance for each animal.